Wiskott-Aldrich syndrome protein regulates autophagy and inflammasome activity in innate immune cells

Nat Commun. 2017 Nov 17;8(1):1576. doi: 10.1038/s41467-017-01676-0.

Abstract

Dysregulation of autophagy and inflammasome activity contributes to the development of auto-inflammatory diseases. Emerging evidence highlights the importance of the actin cytoskeleton in modulating inflammatory responses. Here we show that deficiency of Wiskott-Aldrich syndrome protein (WASp), which signals to the actin cytoskeleton, modulates autophagy and inflammasome function. In a model of sterile inflammation utilizing TLR4 ligation followed by ATP or nigericin treatment, inflammasome activation is enhanced in monocytes from WAS patients and in WAS-knockout mouse dendritic cells. In ex vivo models of enteropathogenic Escherichia coli and Shigella flexneri infection, WASp deficiency causes defective bacterial clearance, excessive inflammasome activation and host cell death that are associated with dysregulated septin cage-like formation, impaired autophagic p62/LC3 recruitment and defective formation of canonical autophagosomes. Taken together, we propose that dysregulation of autophagy and inflammasome activities contribute to the autoinflammatory manifestations of WAS, thereby identifying potential targets for therapeutic intervention.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Animals
  • Autophagy / genetics
  • Autophagy / immunology*
  • Bacterial Load / immunology
  • Cell Line, Tumor
  • Dendritic Cells / immunology
  • Enteropathogenic Escherichia coli / immunology
  • Humans
  • Immunity, Innate / immunology
  • Inflammasomes / immunology*
  • Interferon Type I / immunology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Monocytes / immunology
  • NLR Family, Pyrin Domain-Containing 3 Protein / immunology
  • Nigericin / pharmacology
  • Septins / metabolism
  • Shigella flexneri / immunology
  • THP-1 Cells
  • Toll-Like Receptor 4 / immunology
  • Wiskott-Aldrich Syndrome / immunology*
  • Wiskott-Aldrich Syndrome / metabolism
  • Wiskott-Aldrich Syndrome Protein / genetics*
  • Wiskott-Aldrich Syndrome Protein / metabolism*

Substances

  • Inflammasomes
  • Interferon Type I
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • NLRP3 protein, human
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • WAS protein, human
  • Was protein, mouse
  • Wiskott-Aldrich Syndrome Protein
  • Septins
  • Nigericin